American River Levees

USACE and the State of California issued a draft environmental document for a 45-day public review from 22 December 2023 thru 4 February 2024. The American River Common Features Supplemental Environmental Impact Statement/Subsequent Environmental Impact Report (SEIS/SEIR) can be found here (link: ARCF_Draft-SEIS-SEIR_Dec2023).

Public comments will be accepted from December 22, 2023 until February 5, 2024 and can be submitted to ARCF_SEIS@usace.army.mil and PublicCommentARCF16@water.ca.gov. Response to written comments will be published in the Final SEIS/SEIR.

Two virtual public meetings will be held.

• 10 January 2024
• 16 January 2024

Meeting information will be posted in advance at www.sacleveeupgrades.com.

Contract 3A – This site will be constructed along the left bank of the American River at the Business 80 crossing. We anticipate constructing approximately 2,400 linear feet of bank protection improvements at this location in summer 2025. Vegetation clearing onsite will commence in spring 2025.

Contract 3B North & South - Since much of the Lower American River is constrained by a narrow flood plain there are other areas which must be protected against erosion. Erosion protection measures will be constructed upstream of Howe Avenue under the Contract 3B North & South project. This work is anticipated to occur in the 2026-2027 timeframe. See Question 1 for how to receive more information and provide comments on this work.

With the 2017 completion of a new auxiliary spillway at Folsom Reservoir (which can now release up to 160,000 cubic feet per second (cfs), combined with improvements to the levee system for seepage and stability concerns, the ability to manage large flood events has greatly improved. Erosion of the levee system must now be addressed to bring the entire system up modern standards and safely accommodate the increased flow.

Several levee sections along the American River were identified as being susceptible to significant erosion from the higher, longer releases from Folsom Dam. The proposed bank protection work will armor the riverbank to reduce and prevent erosion which, if left unaddressed, could result in levee failure.

In order to construct the bank protection measures, some trees and shrubs located in the project footprint will need to be removed prior to the start of construction. Vegetation removal work typically occurs between October 1 and April 30, prior to bird nesting season. Most of the vegetation affected by project activities is located on lands owned by the City of Sacramento and the County of Sacramento. The project sponsors are working directly with these respective agencies, including Sacramento County Regional Parks, to facilitate removal of the vegetation necessary to accommodate the project.  Each site will be revegetated  with appropriate native species (on-site mitigation) and additional off-site mitigation (plantings) will be created within the parkway.

Our design engineers developed and planned erosion protection measures to be as effective as possible while causing the least amount of impact to the existing environment. Only vegetation that is directly affected by construction is removed. In many cases designs have been revised to avoid high value habitat and recreational features such as mature trees. The type of improvements associated with erosion protection typically involve placing rock along the riverbank, covering it with soil to establish planting benches and revegetating the bank. The project features cannot be properly installed around existing vegetation located in the project footprint. This means that if the material is in the construction footprint, it would be removed prior to the installation of the protective rock materials.